Surface Tension Of Binary Mixtures Research Articles

Surface tension of binary mixtures of dimethylsulfoxide + methanol, ethanol and, propanol between 293.15 and 308.15 K

The main aim of this work is to study the interface of dimethylsulfoxide+n-alkanol mixtures. To achieve this aim, first, the surface tension of (dimethylsulfoxide+methanol, ethanol, and propanol) was measured as a function of mole fraction and temperature. These measurements were conducted in the temperature range of (293.15–308.15) K and atmospheric pressure. Then the surface tensions of binary mixtures were correlated by Shereshefsky model and excellent results were obtained. The average percent deviation in correlation of surface tension of studied mixtures was 0.7%. Based on Shereshefsky model, the standard Gibbs energy of adsorption and the free energy change in the surface region were calculated. The free energy change was used to obtain the excess number of molecular layers in the surface region. Additionally, the extended Langmuir model was applied. The required parameters of the model were adjusted, the standard Gibbs energy of adsorption was calculated, and positive or negative deviations from ideality were determined. Also surface compositions were calculated by using extended Langmuir model. In addition to these two methods, a predictive model based on the equality of the chemical potential of species in the interface and bulk liquid was used to predict surface compositions and surface tension of mixtures. Additionally, by using surface tensions of studied mixtures at different temperaturs, specific surface enthalpy and specific surface entropy were calculated for (dimethylsulfoxide+n-alkanol) mixtures.

Experimental measurements and modeling of solvent activity and surface tension of binary mixtures of polyvinylpyrrolidone in water and ethanol

In this paper, the density (?), viscosity (?) and surface tension (?) of solutions of poly(vinyl pyrrolidone) (PVP) with molecular weights of 25000 (K25) and 40000 g mol-1 (K40) in water and ethanol were measured in the temperature range 20?65?C and at various mass fractions of polymer (0.1, 0.2, 0.3 and 0.45). The solvent activity measurements were performed at 45 and 55?C. Thereafter, two thermodynamic models for predicting the solvent activity and surface tension of binary polymer mixtures (PVP in water and ethanol) were proposed. The Flory?Huggins theory and Eyring model were employed to calculate the surface tension of the solution and the solvent activity, respectively. Additionally, the proposed activity model was dependent on the density and viscosity of the solution. Afterwards, the ability of these models at various temperatures and mass fractions were investigated by comparing the results with the experimental data. The results confirmed that, in the investigated temperature range, these models have good accuracy.

Effect of temperature and composition on the surface tension and surface properties of binary mixtures containing DMSO and short chain alcohols

Surface tension of binary mixtures of methanol, ethanol and isopropanol with DMSO (dimethyl sulfoxide) was measured over the whole range of composition at atmospheric pressure of 82.5kPa within the temperatures between (298.15 and 328.15)K. The experimental measurements were used to calculate in surface tension deviations (Δσ). The sign of Δσ for all temperatures is negative (except of methanol/DMSO system) because of the factors of hydrogen bonding and dipole–dipole interactions in the DMSO-alcohol systems. Surface tension values of the binary systems were correlated with FLW, MS, RK and LWW models. The mean standard deviation obtained from the comparison of experimental and calculated surface tension values for binary systems with three models (FLW, MS and RK) at various temperatures is less than 0.83. Also, the results of the LWW model were used to account for the interaction energy between alcohols and DMSO in binary mixtures. The temperature dependence of σ (surface tension) at fixed composition of solutions was used to estimate surface enthalpy, Hs, and surface entropy, Ss. The results obtained show that the values of the thermodynamic parameters for alcohol/DMSO mixtures decrease with increasing alkyl chain length of alcohol. Finally, the results are discussed in terms of surface mole fraction and lyophobicity using the extended Langmuir (EL) isotherm.

Surface Tension Estimation of Binary Mixtures of Organic Compounds Using Artificial Neural Networks

The surface tension of binary mixtures at different temperatures and compositions is required in much scientific and technological research. Therefore, having an exact correlation between surface tension and easily accessible physical properties is essential. In this work, the sensitivity of the surface tension to some physical properties was studied by using artificial neural networks (ANNs) to find the most effective ones. Furthermore, ANNs were used to estimate the surface tension of binary systems as a function of the most effective physical properties including critical pressure, reduced temperature, acentric factor, and molar density. The experimental data, collected for training and verifying the networks, include various materials such as alkanes, alkenes, aromatics, alcohols, organic acids, as well as chlorine, iodine, sulfur, nitrogen, and fluorine-containing compounds in the composition ranges from 0 to 100 mole percent, and temperatures between 116 K and 393 K. The average absolute relative deviation (AARD) of the most accurate network, obtained for all 2038 data points regarding 83 binary mixtures, is 1.75%.

Densities and surface tensions of binary mixtures of biodiesel, diesel, and n-butanol

Density and surface tension have been measured for mixtures of biodiesel+n-butanol, biodiesel+diesel, and diesel+n-butanol over the entire concentration range at 283.15 K and 293.15 K and atmospheric pressure, with the combined expanded uncertainties of 1.32 kg·m−3 and 1%, receptively. Densities were determined by a single-sinker densimeter; surface tensions were measured using the surface laser light scattering method. The experimental data showed that densities and surface tensions decreased as temperature increased. The excess surface tensions and excess densities were all negative, and further fitted to the Redlich-Kister equation.

Surface Tension of Binary Mixtures of 2,2,4-Trimethylpentane +1-Alkanols from 298.15 to 323.15 K

Surface tension of binary systems of 2,2,4- trimethylpentane with 1-alkanols (ethanol, 1-propanol, 1-pentanol, 1-hexanol, or 1-heptanol) were measured at several different temperature and atmospheric pressure over the whole range of composition using the surface laser light scattering method, and the combined expanded uncertainties are less than 1%. The excess surface tensions, σE, for these binary mixtures are calculated and fitted to the Redlich–Kister type equation, and the regression parameters and the standard deviations of the fitting are given. All of the σE values are negative over the whole composition range for these systems and decrease with the temperature increasing. Surface tensions were also used to estimate surface entropy, Sσ, and surface enthalpy, Hσ. These results may be useful for the development of the hydrocarbon fuels.

Densities, Viscosities, Refractive Indices, and Surface Tensions of Binary Mixtures of 2,2,4-Trimethylpentane with Several Alkylated Cyclohexanes from (293.15 to 343.15) K

Densities and viscosities have been measured over the whole composition ranges for the binary mixtures of 2,2,4-trimethylpentane with methylcyclohexane, ethylcyclohexane, or n-butylcyclohexane at temperatures T = (293.15 to 343.15) K and atmospheric pressure. Meanwhile, the refractive indices and surface tensions were measured at T = (293.15 to 323.15) K and T = (293.15 to 308.15) K, respectively. The excess molar volumes, VmE, the viscosity deviations, Δη, and the surface tension deviations, Δγ, for these binary systems are calculated and fitted to the Redlich–Kister equation, and the regression coefficients and the standard deviations of the fittings are given. All of the VmE, Δη and Δγ values are negative over the whole composition range for these systems. The values of ΔnD for these binary mixtures are all small, even negligible. These results may be useful for the development of the hydrocarbon fuels.

Prediction of surface tension of binary mixtures with the parachor method

The parachor method for the estimation of the surface tension of binary mixtures is modified by considering temperature-dependent values of the parachor parameters. The temperature dependence is calculated by a least-squares fit of pure-solvent surface tension data to the binary parachor equation utilizing the Peng-Robinson equation of state for the calculation of equilibrium densities. A very good agreement between experimental binary surface tension data and the predictions of the modified parachor method are found for the case of the mixtures of carbon dioxide and butane, benzene, and cyclohexane, respectively. The surface tension is also predicted for three refrigerant mixtures, i.e. propane, isobutane, and chlorodifluoromethane, with carbon dioxide.

Density, Viscosity, Speed of Sound, Bulk Modulus, and Surface Tension of Binary Mixtures of n-Heptane + 2,2,4-Trimethylpentane at (293.15 to 338.15) K and 0.1 MPa

In this work, the physical properties of binary mixtures of n-heptane and 2,2,4-trimethylpentane were measured. Density and speed of sound were measured at temperatures ranging from (293.15 to 338.15) K, and viscosity was measured at temperatures ranging from (293.15 to 333.15) K. At 298.15 K, pure component values for heptane of 679.61 kg·m–3, 0.389 mPa·s, and 1130.1 m·s–1 for density, viscosity, and speed of sound, respectively, agree with literature values. Similarly for 2,2,4-trimethylpentane, the values of 687.70 kg·m–3, 0.501 mPa·s, and 1081.7 m·s–1 for density, viscosity, and speed of sound, respectively, agree with literature values. Density mole fraction and temperature data were fit to a second-order polynomial. Bulk moduli ranged from (551.7 to 907.1) MPa over (293.15 to 338.15) K. Viscosity mole fraction data were fit using the three-body McAllister model, while the viscosity deviations were fit to a Redlich–Kister type equation. For the mixtures, an increase in mole fraction of 2,2,4-trimethy...

Density, Viscosity and Surface Tension of Binary Mixtures of 1-Butyl-1-Methylpyrrolidinium Tricyanomethanide with Benzothiophene.

The effects of temperature and composition on the density and viscosity of pure benzothiophene and ionic liquid (IL), and those of the binary mixtures containing the IL 1-butyl-1-methylpyrrolidynium tricyanomethanide ([BMPYR][TCM] + benzothiophene), are reported at six temperatures (308.15, 318.15, 328.15, 338.15, 348.15 and 358.15) K and ambient pressure. The temperature dependences of the density and viscosity were represented by an empirical second-order polynomial and by the Vogel–Fucher–Tammann equation, respectively. The density and viscosity variations with compositions were described by polynomials. Excess molar volumes and viscosity deviations were calculated and correlated by Redlich–Kister polynomial expansions. The surface tensions of benzothiophene, pure IL and binary mixtures of ([BMPYR][TCM] + benzothiophene) were measured at atmospheric pressure at four temperatures (308.15, 318.15, 328.15 and 338.15) K. The surface tension deviations were calculated and correlated by a Redlich–Kister polynomial expansion. The temperature dependence of the interfacial tension was used to evaluate the surface entropy, the surface enthalpy, the critical temperature, the surface energy and the parachor for pure IL. These measurements have been provided to complete information of the influence of temperature and composition on physicochemical properties for the selected IL, which was chosen as a possible new entrainer in the separation of sulfur compounds from fuels. A qualitative analysis on these quantities in terms of molecular interactions is reported. The obtained results indicate that IL interactions with benzothiophene are strongly dependent on packing effects and hydrogen bonding of this IL with the polar solvent.Electronic supplementary materialThe online version of this article (doi:10.1007/s10953-014-0257-1) contains supplementary material, which is available to authorized users.

Viscosity and surface tension of glycerol + N-methyl-2-pyrrolidone mixtures from 293 to 323 K

The viscosity and surface tension of binary mixtures of glycerol (1) + N-methyl-2-pyrrolidone (2) at T = 293, 298, 303, 308, 313, 318, and 323 K and at atmospheric pressure are reported. The Jouyban–Acree model was used for mathematical correlation of measured data. The average percentage deviation was used as an accuracy criterion. Derived properties from measured thermophysical properties, including deviations in viscosity and surface tension; the enthalpy, entropy and Gibbs energy of flow activation; standard enthalpy and entropy of surface formation data were reported.

Equilibrium surface tension and the interaction energy of DMSO with tert-butyl alcohol or iso-amyl alcohol at various temperatures

Surface tension of binary mixtures of tert-butyl alcohol (TBA) and iso-amyl alcohol (IAA) with DMSO (dimethyl sulfoxide) were measured over the entire concentration range at pressure of 82.5kPa at temperatures between (298.15 and 328.15)K. Correlating the surface tension and surface tension deviation of the above mentioned binary systems was performed with empirical and thermodynamic based models. The average relative error obtained from the comparison of experimental and calculated surface tension values for the two binary systems with five models at various temperatures is less than 2%. The effect of temperature on the interaction energy values in binary mixtures has been used to obtain information about solute structural effects on DMSO. Also, the experimental data were used to evaluate the nature and type of intermolecular interactions in binary mixtures.

Standard Gibbs energy of adsorption and surface properties for ionic liquids binary mixtures

A classical thermodynamic model for the first time is used to derive an equation for the standard Gibbs energy of adsorption and surface properties for ionic liquids binary mixtures. Where experimental surface tension of the mixtures is available, the agreement between the calculated and the experimental data is found to be very good. Bulk mole fraction and surface tension of one of the pure component are necessary inputs for this equation. In addition, to find more information about surface structure of binary mixtures, the surface tension of binary mixtures has been studied using extended Langmuir model (EL).

Surface Tension of Binary Mixtures of 1-Alkyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquids with Alcohols

New experimental surface tension data have been provided at 283.15, 298.15, 313.15 K and atmospheric pressure for binary mixtures of 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide and 1-octyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ionic liquids with the alcohols: methanol, ethanol, 1-propanol, 2-propanol, l-butanol and 1-pentanol. The experimental results show that the surface tensions of these mixtures depend systematically on the alkyl chain length of the ionic liquid and alcohol, composition and temperature. Surface tension changes on mixing have been calculated and adequately fitted by the Redlich–Kister polynomial equation. The adjustable parameters and the standard deviations between experimental and calculated values are reported.

Surface tensions of binary mixtures of ionic liquids with bis(trifluoromethylsulfonyl)imide as the common anion

While values for thermophysical properties of ionic liquids are becoming widely available, data for ionic liquid mixtures are still scarce. In an effort to overcome this limitation and understand the behavior of ionic liquid mixtures, novel data for the surface tension of mixtures composed of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C4mim][NTf2], with other ionic liquids with a common anion, namely 1-butyl-2,3-dimethylimidazolium, [C4C1mim]+, 3-methyl-1-propylpyridinium, [C3mpy]+, 1-methyl-1-propylpyrrolidinium, [C3mpyr]+, and 1-methyl-1-propylpiperidinium, [C3mpip]+, were measured at T=298.2K and atmospheric pressure over the entire composition range. From the surface tension deviations derived from the experimental results, it was possible to infer that the cation alkyl chain length of the second ionic liquid constituting the mixture has a stronger influence in the ideal mixture behavior than the type of family the ionic liquid cation belongs to. The Gibbs adsorption isotherms, estimated from the experimental values, show that the composition of the vapor–liquid interface is not the same as that of the bulk and that the interface is richer in the ionic liquid with the lowest surface tension, [C4mim][NTf2].

Prediction of surface tension and surface properties of organic binary mixtures

The Sprow–Prausnitz equation is employed to describe quantitatively the nature, properties and compositions of surface layers in binary liquid mixtures. Wide variety application, high accuracy, and required parameters that are normally easy to obtain are advantages of Sprow–Prausnitz equation compared to other methods.Bulk mole fraction, surface molar area and surface tension of pure component are necessary inputs for this equation. UNIFAC group contribution method is also applied into account for the non-ideality of the bulk liquid as well as that of the surface layer. The average relative error obtained from the comparison of experimental and calculated surface tension values for 154 binary systems with different surface tension behaviors show the model has good accuracy in comparison with other predictive equations. In addition to find more information about surface structure of binary mixtures, surface tension of binary mixtures has been studied using extended Langmuir model (EL).

Study of surface tension and surface properties of binary systems of DMSO with long chain alcohols at various temperatures

Surface tensions of binary mixtures of DMSO (dimethyl sulphoxide) with a series of long chain aliphatic alcohols (1-propanol, 1-butanol, and 1-hexanol) were measured as a function of composition using the ring detachment method in the temperature range between (288.15 and 328.15)K. The surface tension results are used to describe quantitatively the nature, properties, and compositions of surface layers in binary liquid mixtures. The temperature influence on the behaviour of surface tensions and surface properties of binary mixtures has often been used to obtain information about solute structural effects on DMSO. The surface tension of the above mentioned binary systems were correlated with empirical and thermodynamic based models. The average relative error obtained from the comparison of experimental and calculated surface tension values for 15 binary systems with three models is less than 1%. In addition to finding more information about the surface structure of binary mixtures, surface mole fraction was calculated using an extended Langmuir model (EL). The temperature dependence of σ at fixed composition of solutions was used to estimate surface enthalpy, Hs, and surface entropy, Ss. The results provide information on the molecular interactions between the unlike molecules that exist at the surface and the bulk.

Surface study of binary mixtures containing chlorinated and oxygenated compounds

We report in this work, experimental surface tensions for binary mixtures of isomeric chlorobutanes with butyl ethyl ether or diisopropyl ether from T=283.15K to 303.15K measured with a drop volume tensiometer. The surface tension data have been correlated with a Redlich–Kister type equation. More information about the surface behaviour can be obtained combining these results with previously reported VLE measurements to calculate the excess surface composition of ether in the mixture. Finally, the results have been compared to the predictions obtained using a group contribution method.

Density and surface tension of binary mixtures of 1-ethyl-3-methylimdazolium nitrate with alcohols

Abstract New experimental data of densities and surface tensions are presented for the binary mixtures of the ionic liquid 1-ethyl-3-methyl imidazolium nitrate ([EMIM]NO 3 ) with methanol and ethanol. Measurements were performed at 298.15 K and atmospheric pressure, covering the whole composition range. Excess molar volumes V E and the surface tension deviations δγ have been determined. For the excess molar volumes of binary mixture, there is a region of negative V E at low IL mole fraction, passing through a minimum and then V E increases and becomes positive, showing maximum at higher IL mole fraction. It is shown that the surface tension deviations δγ of [EMIM]NO 3 + methanol system are positive but those of [EMIM]NO 3 + ethanol system are negative over the entire mole fraction range.

Surface Tension of Binary Mixtures of 1-Alkyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquids: Experimental Measurements and Soft-SAFT Modeling

Ionic liquids have attracted a large amount of interest in the past few years. One approach to better understand their peculiar nature and characteristics is through the analysis of their surface properties. Some research has provided novel information on the organization of pure ionic liquids at the vapor-liquid interface; yet, a systematic study on the surface properties of mixtures of ionic liquids and their organization at the surface has not previously been carried out in the literature. This work reports, for the first time, a comprehensive analysis of the surface organization of mixtures of ionic liquids constituted by 1-alkyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ionic liquids, [C(n)mim][NTf(2)]. The surface tension of mixtures composed of [C(4)mim][NTf(2)] + [C(n)mim][NTf(2)] (n = 1, 2, 5, 6, 8, and 10) was experimentally determined, at 298.2 K and atmospheric pressure, in the whole composition range. From the experimental data, the surface tension deviations and the relative Gibbs adsorption isotherms were estimated showing how the surface composition of an ionic liquid mixture differs from that of the liquid bulk and that the surface is enriched by the ionic liquid with the longest alkyl chain length. Finally, the soft-SAFT equation of state coupled with the density gradient theory (DGT) was used, for the first time, to successfully reproduce the surface tension experimental data of binary mixtures of ionic liquids using a molecular-based approach. In addition, the DGT was used to compute the density profiles of the two components across the interface, confirming the experimental results for the components distribution at the bulk and at the vapor-liquid interface.